Percussion mechanism for rotary drilling apparatus



Sept. 29, 1964 H. J. HAWTHORNE 3,150,728-

PERCUSSION MECHANISM F QR ROTARY DRILLING APPARATUS Filed Sept. 15, 1959 4 Sheets-Sheet 1 l0 INVENTOR H E R a E RT J. HmmozzNg ATTORNEYS p 29, 1964 H. J. HAWTHORNE 3,150,728

PERCUSSION MECHANI ISM FOR ROTARY DRILLING APPARATUS Filed Sept. 15, 1959 4 Sheets-Sheet 2 Fig. 6

Fig 3 INVENTOR E HERBERT J. Hmumozui ATTORNEYS P 29, 1954 H. J. HAWTHORNE PERCUSSION MECHANISM FOR ROTARY DRILLING APPARATUS 4 Sheets-Sheet 5 Filed Sept. 15, 1959 INVENTOR H RBERT J. Hmmozm.

BY $411M 6 1- (iM ATTORNEYS HERBERT J. HAWTHORNE H. J. HAWTHORNE PERCUSSION MECHANISM FOR ROTARY DRILLING APPARATUS MB f .ZL&

A I F f m A I I K mi a Sept. 29, 1964 Filed Sept. 15, 1959 BY W 0 4? I W ATroRNEw United States Patent 3,150,723 PERCUSSION MECHANISM FOR ROTARY DRILLING APPARATUS Herbert J. Hawthorne, P.0. Box 7366, Houston, Tex. Filed Sept. 15, 1959, Ser. No. 840,067 3 Claims. (ill. 175299) This application relates to drilling and more particularly to improved precussion hammer mechanism for use in the apparatus and method disclosed in copending application Serial No. 840,068 filed concurrently herewith.

In the above-mentioned copending application there is disclosed a method of drilling earth formation which utilizes apparatus of the type conventionally employed in rotary drilling. The novelty of the above-mentioned application resides in the realization that the drilling operation can be greatly improved by superimposing upon the conventional rotary drilling equipment a series of downward percussion blows. An object of the present invention is the provision of a percussion hammer mechanism for performing the function noted above, such mechanism being operable by means of the rotation imparted to the drill string.

Another object of the present invention is the provision of a percussion hammer mechanism of the type described having improved means for effecting a series of rapid percussion blows for transmittal to a rotary drilling string, such means being operable by rotative energy, preferably the energy of rotation utilized in the drilling installation.

Still another object of the present invention is the provision of a percussion hammer mechanism of the type described which is simple in construction and operation and which is economical to manufacture and maintain.

These and other objects of the present invention will become more apparent during the course of the following detailed description and appended claims.

The invention may best be understood with reference to the accompanying drawings wherein an illustrative embodiment is shown.

In the drawings:

FIGURE 1 is a fragmentary cross-sectional view of an oil well installation showing one manner in which a percussion hammer mechanism embodying the principles of the present invention is employed therein;

FIGURE 2 is a view similar to FIGURE 1 showing another manner in which the percussion hammer mechanism of the present invention is employed therein;

FIGURE 3 is a Vertical sectional view of one form of a percussion hammer mechanism embodying the principles of the present invention:

FIGURE 4 is a cross-sectional view taken along the line 44 of FIGURE 3;

FIGURE 5 is a fragmentary cross-sectional view taken along the line 55 of FIGURE 3;

FIGURE 6 is a front elevational view of the structure shown in FIGURE 5;

FIGURE 7 is a top plan view with parts broken away of the casing of the hammer mechanism shown in FIG- URE 3;

FIGURE 8 is a fragmentary cross-sectional view taken along line 8-8 of FIGURE 7;

FIGURE 9 is a fragmentary vertical sectional view with parts broken away of the upper portion of another form of a percussion hammer mechanism embodying the principles of the present invention; and

FIGURE 10 is a view similar to FIGURE 9 illustrating the lower portion of the percussion hammer mechanism illustrated in FIGURE 9.

Referring now more particularly to the drawings, there is shown in FIGURES l and 2 a drilling installation of the type disclosed in copending application Serial No.

"ice

840,068 illustrating two possible ways in which a percussion hammer mechanism, embodying the principles of the present invention and generally indicated at 18, could be employed therein. As shown in FIGURES 1 and 2 the drilling installation includes a rotary type drilling bit, designated generally by reference character 10, connected to a device usually termed a kelly, designated generally by reference character 12, for imparting rotary motion to the drag bit for drilling hole 14 in the formation. Intervening between the bit 10 and the kelly 12 is a length of conventional structure, usually in hollow tubular form, sometimes referred to in the trade as drill string or drill rod. In FIGURE 1 this structure is designated by reference character 16. In FIGURE 2 the equivalent member appears in two sections designated 16A and 1&3.

One manner in which the percussion hammer mechanism 18 of the present invention may be employed in a drilling installation of the type disclosed in the abovementioned copending application is shown in FIGURE 1, wherein the percussion hammer mechanism 18 is used above the surface 20 of the formation. The kelly 12 may be above or below the hammer mechanism 18, being shown below the hammer mechanism in FIGURE 1. A different manner of employing the percussion hammer mechanism 18 of the present invention is shown in FIG- URE 2. In this case, the hammer mechanism 18 is used down in the hole intermediate the bit It) and the formation surface 20. The dimension L shown in FIG- URE 2 is used for the purpose of explaining that the distance from the bit to the percussion hammer mechanism 18 may be different from one installation to another. The hammer mechanism may be located immediately on the bit It) or a considerable distance up the drill string. The latter case of course merges with the case shown in FIGURE 1 where the hammer mechanism is above the surface of the formation. In any of these cases the compressional waves generated by the percussion hammer mechanism are transmitted through the medium of the drill string to the cutting edges of the rotary bit 10. In the operation of the installation shown in FIGURES 1 and 2, the kelly device is actuated in any of the usual ways so that continuing rotation is imparted to the rotary drag bit 10.

The bit 10 will be caused to exert a downward force on the bottom of the hole being drilled in the formation due to the natural weight of the bit It and the drill string attached to and bearing down on the bit. As is well known practice, particularly where the hole is shallow, if the natural weight of the bit, the drill string and associated parts is not heavy enough to exert sufiicient rotary drilling force, a downward force may be created upon the kelly so as to add to the force of the bit against the formation. One well known way of increasing the drilling force is to have the kelly mounted for example as on a truck, with provision for jacking the truck up on the kelly so as to add the weight of the truck to the forces of the bit against the formation.

However there are cases where the hole becomes so deep that natural weight of the bit and drill string creates forces of the bit against the formation in excess of those which can be tolerated. In this type of situation, it is known to actually exert an upward force on the upper end of the drill string to take some of the load off of the bit. This is a situation intended to be applicable to the FIG- URE 2 arrangement, where upward forces may actually be exerted through the medium of the swivel component 22. In any case where an upward force is being exerted on the upper end of the drill string to relieve the stress upon the bit, there will be a certain point in the string between the bit and the swivel whereat, moving downwardly along the string, the internal stresses in the string changed from tensile stresses to compressional stresses. This can be calculated in advance from knowledge of the mass per unit length of the structure making up the drill string. The dimension L in FIGURE 2, from the bit to the location of the hammer mechanism 13 is intended to denote the length of drill string wherein compressional stresses exist during an operation where upward forces are being exerted on the swivel.

It has been found to be preferably practical to locate the hammer mechanism no further above the bit than the distance L as defined above, when upward forces are applied to the upper end of the drill string. It appears that the percussion blows are transmitted to the bit with least attenuation when these waves need not travel through the part of the drill string under tension.

To complete the explanation of FIGURES l and 2, it may be added that usual rotary bit drilling calls for passage of flushing fluid downwardly through the interior of the drill string. Upon reaching the bit, ports are provided for this flushing of fluid to emerge in the vicinity of the cutting edges, and the fluid then passes upwardly in the hole, carrying with it the cuttings, to a suitable cap structure 24 at the surface of the formation, which has a fluid outlet means 26 for exhausting the fluid with cuttings. Flushing fluid may be entered into the drill string by a suitable hose or like means 28 associated with the swivel structure 22.

Referring now more particularly to FIGURES 38, there is shown one form of a hammer mechanism embodying the principles of the present invention. As best shown in FIGURE 3, a length of the drill string or rod 16 is provided with a slightly enlarged portion existing between oppositely facing shoulders 16 and 16". At the top a circular plate 110 fits string 16 at shoulder 16, and at the bottom a circular plate 112 fits string 16 at shoulder 16". A cylindrical casing 114 joins plates 11%) and 112 by virtue of a series of clamping bolts 116 extending through the upper and lower plates and upper and lower flanges 111 fixed to the casing 114.

In order to prevent foreign material entering the hammer chamber, typical resilient sealing rings 113 may be employed between the stationary plates 111 112 and the drill string 16. To facilitate assembly, the upper sealing ring 113 is preferably retained by a screw threaded member 115, freely rotatable upon drill string 16 and threaded into plate 110.

Intermediate the ends of casing 114 and fixed thereto is a circular plate 118 having an aperture in the center in which string 16 is freely rotatable. As best shown in FIG- URE 4, plate 118 has spaced around it a plurality of apertures 120 in which are slidably positioned a plurality of hammer members 122. Each hammer member 122 is characterized by a shoulder 124 intermediate its length for receiving one end of a spring 126 which is confined under compression by having its upper end rest in an annular groove 128 in the plate 11 Also within the casing 114 resting on the plate 112 and firmly attached to the string 16 is an anvil member 130. Immediately above the anvil member 130 is a cam member 132, fixed to the drill string 16 so as to rotate therewith. If desired, members 136 and 132 may be integral. The basic requirement of cam member 132 is that it rotate with the drill string. The basic requirement of anvil member 130 is that it be firmly attached to the drill string so that percussion blows generated therein will be transmitted to and travel downwardly through the drill string.

The cam member 132 extends only partially around the complete circle, as best seen in FIGURES and 6. At the beginning of the cam member, so to speak, there is a hammer pick-up point or edge 134 (FIG. 5). The thickness of the cam member gradually increases (FIG. 6) until it reaches its complete thickness at an arcuate end point 136 (FIG. 5).

It should now be apparent that with drill string 16 undergoing rotation, while casing 114, plates and 112 and hammer cage 113 remain stationary, the cam member 132 will sequentially elevate each hammer member 122 against the force of its spring 126 until the end 136 of he cam member passes completely beneath a particular hammer member 122. At this moment the spring 126 will forcibly drive the hammer member into contact with the anvil member 136. Percussion or compressional waves generated by this impact will travel through the anvil member 136 to the drill string 16 and from there to the drilling edges of the bit.

With a plurality of hammer members as shown in FIG- URES 36, it will be appreciated that relatively slow rotation of the drill string 16 will nevertheless result in a high frequency of compressional waves delivered to the cutting edges of the bit. It is preferable that the frequency of the compressional waves be varied by means other than varying the rotation of the drilling string 16. For example, if a lesser frequency is desired, one or more of the hammer members could be removed prior to installation. If a higher frequency is desired, additional hammer mechanisms could be mounted on the drilling string and the number of hammer members employed in such mechanism or mechanisms could be suitably varied in the same manner indicated above.

Referring now more particularly to FIGURES 9 and 10, there is shown another embodiment of a percussion hammer mechanism embodying the principles of the present invention. The hammer mechanism of FIGURES 9 and 10 is adapted to be mounted on the drill string 16 without the necessity of providing shoulders thereon as is the case in the embodiment shown in FIGURES 3-8. As best shown in FIGURE 10, the hammer mechanism includes a tubular anvil member 210 which is rigidly secured to the exterior surface of the pipe string 16 by any suitable means, such as welding or the like. If desired, the anvil member 210 may be provided with a series of circumferentially spaced openings 212 which are utilized to facilitate the welding of the anvil member to the exterior periphery of the drill string at the desired location thereon. Mounted on the drill string 16 for rotational movement thereon above the anvil member 216 is a turnable striking anvil member or ring 214. Rigidly secured to the drill string 16, as by welding or the like, in a position directly above the turnable striking anvil member 214 is a semi-helical wedge-shaped lifting cam member 216 which is equivalent to the cam member 132 previously described.

A hammer member 218 of tubular form is mounted on the drill string 16 above the striking anvil member 214 for rotative movement with respect to the tubing string. The lower end of the tubular hammer member 218 is provided with a substantially semi-circular notch 220 having a longitudinal dimension slightly greater than the longitudinal height or dimension of the cam member 216. If desired, the lower leading edge formed by the notch 226 is formed with an inclined cam surface 222 for engaging the upper surface of the cam member 216.

As best shown in FIGURE 9, the hammer member 218 is maintained in contact with the cam member 216 and the striking anvil member 214 by means of a coil spring 224, having its lower end in engagement with the upper end of the tubular hammer member 218. The upper end of the coil spring 224 engages a non-rigid floating ring 226.

The floating ring 226 is maintained in pre-determined position with respect to the cam member 216 on the drill string 16 by means of upper and lower tubular sections 228 and 231) which are interconnected by an outer tubular casing member 232.

As best shown in FIGURE 10, the lower tubular section is provided with an interior bore 234 which is arranged to snugly embrace the exterior periphery of the tubing string 16. Preferably, suitable sealing means is provided between the bore 234 and the exterior periphery of the drill string 16, as for example, O-ring seal 236. Formed intermediate the ends of the tubular section 230 is an exterior annular flange 238 and the exterior surface of the section above the flange 238 is threaded to engage cooperating threads formed on the lower end of the easing 232. The lower extremity of the tubular casing member 232 engages the shoulder 238 and suitable sealing means, in the form of an O-ring seal 240 or the like, is preferably provided between the tubular sectionand the tubular casing member.

The upper tubular section 228 is similar in construction to the tubular construction 230 and includes a central bore 242 which closely embraces the exterior periphery of the drill string 16. As before, an O-ring seal 244 is preferably provided between the bore 242 and the exterior periphery of the drill string. In addition, the upper tubular section 228 includes an annular flange 246 formed in the exterior periphery thereof intermediate its ends. The portion of the upper tubular section below the flange 246 is exteriorly threaded to receive the interiorly threaded upper end of the casing member 232. As before, the upper extremity of the casing member engages the flange 246 and an O-ring seal 248 is provided between these members to seal the same.

Interposed between the floating ring 226 and the lower extremity of the upper tubular section 228 is one or more split ring sections 250. As shown in FIGURE 9, one split ring 250 is illustrated and it will be understood that where different spring pressures are desired additional rings may be employed between the floating ring 226 and the upper tubular section. Moreover, it can be seen that the spring 224 serves to maintain the casing member and tubular sections connected therewith in a longitudinally fixed position with respect to the tubing string. Thus, the spring serves to resiliently urge the upper tubular section upwardly and since the casing member 232 and lower tubular section 230 are rigid with the upper tubular section, the upper end of the lower tubular section will be urged into engagement with the lower end of the rigid anvil member 210.

It will be noted that the interior diameter of the tubular casing member 232 is sufficiently large to permit the drilling string and the members 210 and 216 rigidly attached thereto to rotate therein. Relative relation between the casing member 232 and the hammer member 218 is prevented by any suitable means such as a longitudinally extending key 252 rigidly secured to the inner periphery of the tubular casing member 232 and extending radially inwardly into a longitudinally extending elongated slot 254 formed in the exterior periphery of the hammer member. It can thus be seen that the hammer member can move longitudinally with respect to the casing member 232 but can not move rotationally with respect thereto.

It will be understood that in operation the tubular casing member 232 is prevented from rotating along with the rotation of the drill string 16 by means such as described above in connection with the embodiment shown in FIG- URES 3-8. That is, where the hammer mechanism of FIGURES 9 and 10 is utilized adjacent the kelly, suitable linkages (not shown) connected to fixed structure, such as the derrick frame or the like, and to the casing member 232 may be provided. Where the hammer mechanism illustrated in FIGURES 9 and 10 is utilized down in the hole, suitable side wall gripping members 156 of the type illustrated in FIGURES 7 and 8 may be utilized. Here only the casing 114 is shown because the internal parts will remain the same. At three positions 120 apart about the casing 114 and intermediate the plates 110 and 112 there is affixed as by welding, protruding wings 150 having channels 152 therein characterized by inturned edges 154 for capturing side wall gripping members 156. The latter are urged outwardly by compression springs 158 mounted between the members 150 and 156. The members 156 include outwardly extending flanges 160 which ride in channels 152 and serve to limit the extent of outward movement of the gripping members, by engagement with the inturned edges 154.

The operative position of members 156 is to be such in relation to the diameter of the hole drilled by a particular bit, that before the complete movement of the members 156 outwardly in the channels 152, the outer end surfaces of members 156 will be pressed firmly against the side wall of the hole. Thus, members 156 will tend to dig into the side wall and prevent rotation of the casing 114 and associated parts which are to remain stationary relative to the rotating drill string 16. It will be appreciated that as drilling progresses the drill string 116 must move downwardly in the hole and in order to permit side wall gripping against rotation but still permit downward (and upward) movement of the hammer mechanism in the hole, the gripping members 156 are provided with sloping surfaces 162, at the tops and bottoms thereof as best shown in FIGURE 8.

The operation of the hammer mechanism of FIGURES 9 and 10 is believed to be apparent from the above description. In brief, it will be noted that the casing member 232 is held against movement about its axis during the rotation of the drill string 16 about its axis. Since the hammer member 218 is also held against rotation with the casing member 232 by means of the key 252, the relative rotation of the drill string will effect movement of the cam member 216 into engagement with the lower end surface 222 of the hammer mechanism causing the hammer mechanism to move longitudinally upwardly against the action of spring 224 during each revolution until the trailing end of the lower surface of the hammer member defined by the notch 220 leaves the upper end of the cam member 216. After this disengagement, the hammer member will be forced downwardly by the action of the spring 224 and its lower surface will strike the turnable anvil member 214. The percussion blow thus delivered to the turnable anvil member 214 will be transmitted by means of a compressional wave to the drilling bit 10 on the lower end of the drill string through the rigid anvil member 212. The purpose of providing the anvil member 214 which is capable of movement with respect to the rigid anvil member 212, is to reduce wear, since the hammer member will strike the rotating anvil member at different positions due to the fact that it is freely movable about its own axis.

It will be understood that where more than one percussion blow per revolution of the drill string for a given speed of rotation is desired, additional hammer mechanisms of the type shown in FIGURES 9 and 10 may be mounted on the drill string at spaced positions thereon.

It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing specific embodiment has been shown and described only for the purpose of illustrating the principles of this invention and is subject to extensive change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

I claim:

1. In an apparatus for drilling earth formations, the combination comprising a sealed casing having a length of drill string extending longitudinally therethrough for rotation with respect to said casing, exterior means on said casing for contacting the earth and preventing rotation of said casing in response to rotation of said drill string, an anvil member within said casing, .a hammer member non-rotatably mounted within said casing for movement toward and away from said anvil member, spring means within said casing resiliently urging said hammer member toward said anvil member, and a cam member mounted within said casing and fixedly secured to said drill string for rotation therewith in the same direction for moving said hammer member gradually away from and then rapidly into effective contact with said anvil member in response to relative rotation between said cam member and said hammer member, said cam member and said hammer member being thereby fixed rotationally with respect to said drill string and said casing to rotate relative to each other in response to relative rotation between said drill string and said casing, said anvil member being mounted with respect to said drill string to transmit to the latter compression waves generated as a result of said hammer member efiectively striking said anvil member, wherein said anvil member is rigidly secured to said drill string and said cam member is rigidly secured to said drill string in spaced relation to said anvil member, and wherein a freely turnable striking anvil member is mounted for rotation about said drill string between said first mentioned anvil member and said cam member.

2. The combination as defined in claim 1 wherein a plurality of said hammer members are mounted in circumferentially spaced relation about said drill string within said casing.

3. The combination as defined in claim 2 including a 8 mounting member having its outer periphery rigidly secured to the inner periphery of said casing, said mounting member having a plurality of circumferentially spaced apertures extending therethrough for receiving said hammer members.

References Cited in the file of this patent UNITED STATES PATENTS 1,554,446 Loy Sept. 22, 1925 1,667,077 Mecom Apr. 24, 1928 1,906,771 Sandstone May 2, 1933 2,013,070 Sheridan Sept. 3, 1935 2,153,883 Foster Apr. 11, 1939 2,228,482 Prebensen Jan. 14, 1941 2,241,712 McNamara May 13, 1941 2,400,853 Stilley May 21, 1946 2,634,951 Snyder Apr. 14, 1953 2,694,551 Snyder Nov. 16, 1954 

1. IN AN APPARATUS FOR DRILLING EARTH FORMATIONS, THE COMBINATION COMPRISING A SEALED CASING HAVING A LENGTH OF DRILL STRING EXTENDING LONGITUDINALLY THERETHROUGH FOR ROTATION WITH RESPECT TO SAID CASING, EXTERIOR MEANS ON SAID CASING FOR CONTACTING THE EARTH AND PREVENTING ROTATION OF SAID CASING IN RESPONSE TO ROTATION OF SAID DRILL STRING, AN ANVIL MEMBER WITHIN SAID CASING, A HAMMER MEMBER NON-ROTATABLY MOUNTED WITHIN SAID CASING FOR MOVEMENT TOWARD AND AWAY FROM SAID ANVIL MEMBER, SPRING MEANS WITHIN SAID CASING RESILIENTLY URGING SAID HAMMER MEMBER TOWARD SAID ANVIL MEMBER, AND A CAM MEMBER MOUNTED WITHIN SAID CASING AND FIXEDLY SECURED TO SAID DRILL STRING FOR ROTATION THEREWITH IN THE SAME DIRECTION FOR MOVING SAID HAMMER MEMBER GRADUALLY AWAY FROM AND THEN RAPIDLY INTO EFFECTIVE CONTACT WITH SAID ANVIL MEMBER IN RESPONSE TO RELATIVE ROTATION BETWEEN 